Semiconductor memories are indispensable components in various electronic device systems. Among semiconductor memories, nonvolatile semiconductor memories demonstrate a unique capability for data storage in case of power failure, and thus have been widely used in various mobile and portable devices, including mobile phones, notebook computers, personal digital assistant (PDA) devices, etc. Resistance random access memories (RRAMs) demonstrate many advantages, such as simple fabrication process, fast read and write speed, high storage density, nonvolatile storage, compatibility with the traditional silicon integrated circuit (IC) technology, etc. Therefore, RRAMs have great application potential in the field of semiconductor memories.
The RRAM is a nonvolatile memory developed based on the electrically-induced-resistance-change effect of some materials. The functional device of the RRAM is a simple metal-insulator-metal (MIM) capacitor. The material of the insulation layer in the MIM capacitor has the electrically-induced-resistance-change property. That is, the resistance of the material used to form the insulation layer in the MIM capacitor can be reversibly changed under the control of specific external signals. Based on the change in the voltage applied on the insulation layer, the resistance of the insulation layer may be changed between a high-resistance state and a low-resistance state, and thus the RRAM may be able to turn on or turn off the current channel. Specifically, when the resistance changes from the high-resistance state (i.e. an off-state) to the low-resistance state (i.e. an on-state), the operation process corresponds to a set operation; when the resistance changes from the low-resistance state (i.e. the on-state) to the high-resistance state (i.e. the off-state), the operation process corresponds to a reset operation.
Further, two diodes (D) with rectification characteristics are integrated in each RRAM (R) device to form a 2D1R memory array structure. When the 2D1R memory array structure is applied to a memory structure, the memory structure may demonstrate advantages of high operation current and low leakage current.
However, the performance of conventional memory structures still needs to be improved. The disclosed memory cells, memory array structures, and methods thereof are directed to solve one or more problems set forth above and other problems in the art.